Analyse Magic

You can learn certain things about the caster or creator of a spell or magic item.

Liber Mysterium  
The Netbook of Witches and Warlocks  
By Timothy S. Brannan and The Netbook of Witches and Warlocks Team

Divination

Level: Witch 4, Sorcerer/Wizard 5
Components: V S
Casting Time: 1 Minute
Range: Touch
Target, Effect, Area: Item Touched
Duration: Instant
Saving Throw: See text
Spell Resistance: Yes

Make an ability check of your relevant casting ability score, plus half your caster level. Then, modify the roll using the following.

If the spell is cast by a famous/well known Spellcaster	+4
Steps taken to disguise the magical aura (Nystuls Magical Aura, etc.)	-5 spell level
Spell or item has been used against you before	+1 each instance
Number of years ago spell was cast or item was created	-1 for each year
Spell or item was cast as a type not available to caster (a divine spell as being analyzed by a wizard, for instance)	-5

At the GM’s discretion, other modifiers may apply. Then, take your result and consult the following.

Condition	DC
Class of the Spellcaster (Witch, Cleric, Wizard, etc.)	10
As above, plus Coven, Religion, or school of specialty (if applicable) of caster	12
As above, plus Alignment of Caster	15
As above, plus name of caster	20
As above, plus time created/cast, and visuals of the caster creating the item or casting the spell.	24
As above, plus reason created/cast	30
As above, plus can analyze anyone else who has used the same item (begin rerolling at a -5 penalty).	35

This spell can be used to analyze spells with a long duration, magical items, magical constructs, undead or aberrations created by wizardry.